Fire retardant paint



United States Patent FIRE RETARDANT PAINT Austin 0. Allen, East Orange, Thomas M. Murray, Morris Plains, and Felix P. Liberti, Totowa, N. J., assignors to Vita-Var Corporation, Newark, N. J., a corporation of New Jersey N0 Drawing. Application June 26, 1953, Serial No. 364,494

12 Claims. (Cl. 106-15) This invention relates to fire retardant paints or coatings which may be used to protect an underlying inflammable structure, including protective and decorative coatings for either exterior or interior use.

The problem of providing a fire-retardant paint or coating is an old one, and many solutions to it have been proposed. It has been recognized that to make an effective fire retardant paint, one or more of the following expedients must be used:

1) The substitution of an incombustible material for a combustible material in a known paint composition;

(2) The addition of an ingredient which, when heated, liberates noninflammable gases to smother the flame;

(3) The addition of an ingredient which, when heated, releases a gas giving intumescent properties to the paint i. c. it bubbles and swells to form a thick cellular mat which serves to insulate the painted structure from the flame;

(4) The addition of an ingredient which will melt when exposed to heat and flux to a glass-like material which tends to retard and prevent the spread of flame.

To be practical as protective and decorative coatings, fire retardant paints must have fire retardant properties as durable under all service conditions as the protective and decorative properties. A paint which retains its protective and decorative properties after its fire retardant properties are lost is dangerous, since it gives an appearance of safety when it is in fact unsafe.

The fire retardant paints of the prior art have not been practical as protective and decorative coatings because:

(1) The exterior finishes do not retain their fire retardant properties after exposure to weather and do not have durability nor give protection equivalent to that of conventional exterior paints;

(2) The interior finishes lose their fire retardant characteristics when washed or when they otherwise come in contact with water.

The mat-forming or intumescent materials suggested in the prior art have been more or less water soluble, so that upon exposure to weather, the fire retarding properties of the paints containing such materials were reduced substantially. The intumescent materials of the prior art have typically been paint pigment components or solid ingredients rather than vehicle components.

The applicants have discovered certain materials which have many of the film-forming properties required in the non-volatile components of paint vehicles, which are insoluble in water and which have outstanding intumescent properties when exposed to flame. At the same time, these materials do not detract from the service properties of the paint, and in some cases actually improve the service properties.

One of the film-forming materials of this type which the applicants have discovered is isano oil, also known as ongokea oil. This oil is obtained by pressing boleko nuts, which are native to Africa. So far as the applicants can determine, there is no known commercial utility for these nuts or their oil in this country.

This intumescent property is not known to exist in any other film-forming vegetable oil. The intumescent qualities of isano oil are remarkable as compared to other vegetable oils and film-forming materials because of the violence of the chemical reaction which takes place when this oil or a film containing it is subjected to heat. This reaction releases gases which cause a swelling and thickening of the film to form an improved insulation for the underlying flammable surface by preventing the underlying flammable surface from reaching the temperature necessary for combustion. It is to be noted that raw isano oil is used since treating or processing it in any manner using heat has been found to destroy this unique intumescent property.

The applicants have also discovered a class of filrnforming intumescent materials suitable for use in paint vehicles. These are nitrogen-containing resinous materials which decompose to liberate gaseous nitrogen or nitrogen-containing gas upon heating. Outstanding in this class are the polyamide resins, although many of the formaldehyde resins, notably melamine, urea and triazine formaldehyde resins have been found to be very satisfactory. For purposes of definition these formaldehyde resins are referred to generically in this specification as the amine formaldehyde resins. For the purposes of the present invention, a polyamide resin may be defined as a product obtained by reacting a polymerized unsaturated vegetable acid with an amine. By way of example, the acid may be dimerized and trimerized linoleic and linolenic acids of soy bean oil, and the amine may be ethylene diamide. Polyamide resins are a known article of commerce. One example of such a resin is Polyamide Resin No. 93, obtainable from General Mills, Inc., Chemical Division.

The applicants have discovered a remarkable synergistic effect from the incorporation of both isano oil and one of the nitrogen-containing resinous materials in a paint vehicle. The applicants have further discovered that the paint vehicle may and preferably should also include conventional film-forming materials, for example, drying or semi-drying oils, alkyd resins, and oleoresinous materials; chlorinated parafiins; and that paint vehicles employing these principles may be so prepared that the desirable qualities of a conventional paint are retained in the resulting product, especially with regard to decorative appearance, ease of application, durability and,

washability, While still retaining superior fire retardant properties.

Since isano oil has film-forming properties, it is possible to make a paint using it as the only non-volatile component of the vehicle. Similarly, the polyamide resins have film-forming properties which make it possible to use them as the only non-volatile component in a paint vehicle. It has also been found that a paint commercially efiective as a fire-retardant paint may be made by using isano oil and polyamide resin as the only non-volatile vehicle components. Any of the paints formulated as suggested immediately above exhibits the outstanding fire retardant properties which are characteristic of paints prepared in accordance with the present invention.

It is greatly preferred, however, to mix the novel intumescent film-forming materials of the present invention with the less expensive conventional film-forming materials, such as those mentioned above, for reasons of economy and also in order to incorporate in the finished paint the desirable properties of such conventional materials, especially with respect to decorative appearance, ease of application, drying time, and protective qualities including durability under conditions of.

weathering, washing and wear.

Paint vehicles may be prepared using a mixture of a drying oil, e. g., linseed oil, and either isano oil or a resinous material selected from the class consisting of polyamide resins and amine formaldehyde resins as the only film-forming materials in the vehicle. It is greatly preferred, however, that paint vehicles prepared in accordance with the present invention should contain from about to about 60% isano oil and from about 5% to about polyarnide resin. They should also contain conventional film-forming material such as a vegetable drying oil, preferably linseed oil, in a proportion of about 15% to 50%.

it has been found that, within the broad ranges of proportions set forth above, particularly successful and desirable results are obtained if the isano oil is between 13% and of the vehicle, the polyamide resin 7% to 11%, and the conventional film-forming material 19% to 40%.

There are set forth below in tabular form eight examples, of paints mixed in accordance with the principles of the present invention, each paint employing both a conventional film-forming material and at least one of the novel intumescent materials. Examples 1 and 11 contain isano oil and polyamide resin. Examples III and 1V contain melamine formaldehyde resin and triazine formaldehyde resin, respectively, in place of the polyarnide resin of Examples 1 and II. Examples V and VI contain isano oil but no nitrogen-containing resin. Examples VII and VIII contain polyamide resin but no isano oil.

In each example there is given the weight and the percentage of each ingredient in the mixture. The percentage of each pigment ingredient in the total pigment, and the percentage of each vehicle ingredient in the total vehicle are also given.

Example I Weight Percent Percent Pigment and other Solid Components (Lbs) Pigment oiP'lpttal ain Titanium Dioxide 100. 0 10. 30 6. 28 292. 0 30. 04 18. 31 148.0 15.21 9. 27 168. 5 17. 33 10. 56 168. 5 17. 33 10. 56 Zinc Oxide 95.0 9. 79 5. 96 Total Pigment 972. o r00. 00 60. '94

Weight Percent Percent Vehicle Components (Lbs.) Vehicle of Total Paint XX Refined Linseed Oil 170. 0 27. 28 10. 66 Raw Isano Oil 170.0 27. 28 10.66 Chlorinated Para-fiin 70%. 70. 0 11. 23 4. 39 Poly-amide #93 Resin 64.0 10.27 4. 01 Cobalt Naphthenate Solution (2% balt as Metal) 5. 5 88 .34 Lead Naphthenate Solution (8% Lead as Metal). 24. 0 3. 85. 1. Manganese Naphthenate Solution (2% Manganese as Metal) V 3. 5 .56 22 Volatile Organic Solvents 116.0 18. 7. 28 Total Vehicle 623. 0 100.00 3906 Grand Totals 1, 595.0 100.- 00 60 Example 11 i Weight Percent Percent Pigment and other Solid Components (Lbs) Pigment of Total Paint Titanium Dioxide 87.0 8.35 5. 16 Zinc Borate 253. 0 24. 29 15. 89 Blane Fixe 128. 0 12.729 8. 04 Lead Sulfate 146.0 14. 02 9. 17 Lead Carbonate 146. 0 14. 02 9. 17 Benzene Sulfony 200. 0 19. 20 '12. 55 Zinc Oxide 81. 5 7. 83 5. 12 Total Pigment i, 041'. 5" i 100. 05 e5. 40

Weight Percent Percent Vehicle Components (Lbs.) Vehicle of Total Paint XX Refined Linseed Oil;. 147. 0 26. 68 9. 23 Raw isano Oil 147. 0 26. 68 9. 23 Chlorinated Parafiiu 60. 5 10. 98 3. Polyamide #93 Resin 55. 2 10. 02 3. 47 Cobalt Naphthenate Solution (2% Cobalt as lVletal) H 4. 7 29 Lead Naphthenate Solution (8% Load as Metal)" 20. s 3.77 1. 30 Manganese i\ h Manganese a Metal) 3.0 .55 .20 Volatile Organic Solvents 112. 8 20. 47 7. 08 34. 60

Example 111 Weight Percent Percent V Pigment and other Solid Components (Lbs) Pigment of Total Paint Titanium Dioxide 100. 0 10.30 6. 41 Zinc Borate 292.0 30. 10 18. 73 Blane Fine 148. 0 15. 22 9, 47 Lead Sulfate. 168. 5 17-. 30 10. 77 Lead Carbonate. 168. 5 17. 30 10.77 Zinc Oxide 95. 0 9. 78 6. 09 Total Pigment 972.0 100. 00 62. 24

Weight Percent 'Percent Vehicle Components (Lbs) Vehicle of Total 7 Paint XX Refined Linseed Oil 170.0 28. 84 10. Raw isano Oil 170.0 28.84 10. Chlorinated Paraffin 70 70. O 11.87 4. Melamine Formaldehyde Resin 64.0 10.86 4. Cobalt Naphthenate Solution (2% Cobalt as Metal) 5. 5 .93 .35 Lead Naphthenate So u (8% Lead as Mietal) 2 .0 4.07 1. 54 Manganese Naphthenat Solution (2% Manganese as Metal) 3. 5 .22 Volatile Organic Solvents. 82. 5 14.00 5. 29 Total Vehicle 5 89. 5 100. 00' 37. 76 Grand Totals 1, 561. 5 100.00

Example IV Weight Percent Percent Pigment and other Solid Components (Lbs) Pigment of Total Paint Titanium Dioxide 100.0 10.30 6. 45 Zinc Borate 292. 0 30. 10 18.85 Blane Fine. 148. 0 15. 22 9. 54 Lead Sulfate..- 168. 5 17. 30 10. 84 Lead Carbonate- 1.68. 5 17. 30 10. 84 Zinc Oxide 95. 0 9. 78 6. 13 Total Pigment 9'72. 0 iobfoo 62.65

Weight Percent 7 Percent Vehicle Components (Lbs) Vehicle. of Total Paint 170. 0 29. 31 10. Raw Isano 0 170.0 29. 31 10.95 Chlorinated Paraflin 70%. 70.0 '12. 10 4. 52 Triazine Formaldehyde Resin 64. O 11.05 4. 13. Cobalt Naphthenate Solution (2% C0- balt as Metal) 5. 5 V 95 .35 Lead Naphthenate Solution (8% Lead I as Metal) 24.0 4.15 1. 55 Manganese Naphthenate Solut'on (2% Manganese as Metal) 3. 5 60 22 Volatile Organic Solvents. 72. 5 12.53 4. Total Vehicle 519.5 100.00 37. as

G nd Tota s,-..---.-- 5 1.5

Example V Example VIII Wei ht Percent Percent Weight PPrceht Percent Pigment and other Solid Components (Lbg) Pigment of Total Pigment and other Sohd Components (LIE) Plgmeht p g 3111 Paint 5 Titanium Dioxide 119.0 15. 43 8. 67 z illt nitt iiifii 353:5 35:53 55:2? Zinc 218- 28-28 1589 Calcium Carhona 76. 12. 76 6. 90 gg ffi g :32 g Magnesmm Smcate 51 Lead oarbonatel I 126. 0 16: 34 9:18 Total Pigment 599.5 100. 00 5409 0 Z111 Oxlde Total Pigments 771. 0 100. 00 56. 19 Weight Percent Percent Vehicle Components (Lbs.) Vehicle 0% git-$11 Weight Percent Percent Vehicle Components (Lbs.) Vehicle of Total Paint 11: 1}efine% ginseed Oil g 29. 71 13. g

aw sano 29. 1 13. Chlorinated Peraifin 70% 73. 0 14. 34 6.58 6% h l ii h g 5 -2 31 Lead Naphthenate Solution 3% Lead P s 3 817 as Metal) 30. 0 5. s0 2. 71 ,13? w 5 14 89 52 Manganese Naphthenate Solution (2% 0C b It g 53 e 0 H 1011 (2% 4 1 68 i g a gg 3 m3 aghthe i:1ate oli1tion Lead Vohme rgamc oven 8 Mas Metal)fih h u rghz y 18.0 2.99 1.31

- anganese ap e113 6 011 0D Total Vehicle 9 0 91 Manganese as Metal) f 2.6 43 19 Grand Totals 1 ma 4 1m 00 Volatile Organic Solvents 224. 5 37. 16. 36 Total Vehicle 601.1 100.00 43.81 Example VI 25 Grand Total 1,371.1 m

- M. The following table sets forth test results Wh1ch Were Weight Percent Percent Pigment and other Solid Components (Lbs.) Pigment ofT otal Obtamed Wlth each of the foresomg elght examples In Pam; each case, sample poplar panels, 6" X 12" X A", were 3 made up and painted, each with two coats of one of the Titanium Dioxide 250. 0 37.20 22.10 Zinc Bums" 180.0 2M9 1592 paints undergomg test. After drying, the panels were tarch 242.0 36.01 21.40 glven a standard burn test which was recommended to us by the Engineer Research and Development Labora- Total Pi ents 672.0 100.00 59.42

gm tones, U. S. Army, Fort Belvoir, Virginia. In this test, h P 35 each panel is placed in a standard cabinet known as a Weig t ercent Percent Vehicle Components (Lbs) Vehicle of Total New York Paint and Varmsh Production Club 'lest Cabi- Paint net, having standard size and ventilation provisions. A on containing 5 cc. of absolute alcohol is laced one I n P Alkyd Resin. 73.8 16.08 6.53 1nch from the face of the panel and igmted. The test iiiifii ite ii arari'tg:3:33:13:33:3: 3313 iii? 2:35 Continues until all burning ceases- The Charred area and Sulphonated oil 4.0 .87 .35 the loss in weight of each panel is measured. The times 20. 0 4. 36 1. 77 at which the flames go out in the fuel cup and oh the Panel M i anese Napilllhghfite Solution (2% 9 0 1 so are also noted. Although other measurements are made anganese as e Volatile organic 1A2 37.95 40 and other crltena are consldcred In evaluating the test re- 459 1 4 8 sults, three of the most important criteria are the percent- Vehicle 0O 5 age loss in weight, the time of persistence of the flame on Grand Totals 1,130.0 100.00 the panel after the alcohol burns out, and the charred area.

The same test is re eated for each aint sample, with Example VII panels which are leached in distilled water for 40 hours W ht P t P t at 120 F. The leached panels are dried for 72 hours 81g ercen Green 0 Pigment and other Solid Components (Lbs.) Pigment of Total at 120 before the bum h results for the Paint leached and unleached panels are given 1n the table. Each test figure in the table represents an average of several Titanium Dioxide 100. 0 10.31 6. 28 tests. By way of contrast, the table sets forth the results 33:8 2 212 of a similar test with a commercially available flame re- Lead Sulfate.-. 168.5 17.37 10.58 sistant paint product. Lead Carbonate" 168.5 17.37 10.58 Table I Zinc Oxide 95. 0 9. 79 5.95

Total Pigment 970'0 00 6O Unleached Panels Leaclled Panels Weight Percent Percent Persist- Char Persist- Char Vehicle Components (Lbs.) Vehicle of Total Percent ence of Area Percent ence of Area 7 Paint Wt. Panel (sq. Wt. Panel (sq Loss Flame in.) Loss Flame in.) (sec.) XX Refined Linseed Oil 340.0 54. 58 21. 34 6 Chlorinated Paraflin 70.0 11. 24 4. 40 Polyamide 93 Resin 64. 0 10. 27 4. 02 Example Cobalt Naphthenate Solution (2% I 4 13.75 5.68 O 13.9 Cobaltas Metal) 5.5 .88 .34 0 19 7.05 1 16.92 Lead Naphthenate Solution (8% Lead 3 18.96 8.06 1 24.8 as Metal) 24.0 3.85 1.51 1 22.28 7.53 -6 19.08 Manganese Naphthenate Solution (2% 7 0 26. 00 9.0 0 20. 49 Manganese as Metal) 3. 5 56 .22 2 18. 67 9. 7 2 31. 30 Volatile Organic Solvents 116.0 18.62 7.28 1 20.56 7.62 1 20.4 VIII 8.26 -2 18.9 8.58 0 22.5 Total Vehicle 623. 0 100. 00 39. 11 Commercial Flame Re- Grand Totals 1,593.0 100. 00 sistant Paint- 8.31 1 21. 38 15.04 -4 44. 28

with the invention produced markedly better results as.

weight loss. than did the prior art com: mercial paint. These improved results are particularly outstanding in the case of the leached panels. The leached panels also show another remarkable improvement in the char area measurement.

By way of comparison between the various examples. formulated in accordance with the present invention, it may be noted that the examples containing both isano oil and polyamide resin (Examples I and II), gave somewhat better results than the examples containing isano oil and other nitrogen-containing resins (Examples III. and IV).

to percentage It may also be observed that Examples I and II gave markedly better results than Examples VII and VIII, which contained no isano oil. Examples V and VI contained isano oil, but no nitrogen containing resin, but the results, although indicating some value, are not as good as in Examples I and II;

It follows that there exists a remarkable synergistic effect from the use of a combination of isano oil and polyamide resin; other nitrogen-containing resinous materials show this efiect to some extenhbut to a lesser degreethan the polyamide resin,

The paint mixtures may be prepared in a conventional manner. One preparation method whichis convenientfor use with Example I listed above is to mix the pigments with the linseed oil, isano oil and chlorinated paraffin components to form a uniform paste; then pass this paste over a conventional roller; mill, set to give a'fineness; of 3-4 on a standard precision fineness gauge, such as the Fineness of Grind Gauge manufactured by Precision Gauge and Tool Co., of Dayton, Ohio. The other vehicle components are then added to this dispersed paste.

In many of the examples given above, the pigment components are selected for their; known fire resistant properties. For example, zinc borate'and zinc oxide are both known to have such proper-ties. In some cases also, a vehicle component has been selected for its fire resistant P p as a p e h hlsr mtcd Pa fiin sed. in all the examples. This material decomposes, when heated, liberating chlorine which tends to smothen the flames.

The mineral spirits mentioned in many of the examples r hydrocarbon a t o w ich may be ep aced. y a volatile organic solvent. The function of'this component in the mixture is simply to reduce. the viseosity to a point where it is suitable for application. The; naphthenates included in the examples are well known dryers, used in many commercial paints. r

While we have described specifically those embodiments ofour invention which are presently preferredymany other modifications of the invention will readily occm to those skilled in the art, andwe therefore intend our invention to be limited only by the appended claims.

We claim as our invention:

1. A.fire:retardant paint etfectiveto form a film having intumescent propertieswhen subjected to heat, comprising pigment, volatile vehicle components and nonvolatile vehicle components consisting essentially of at least 10% raw isano oil and at least 5% of a resinous compound selected from the class consisting of'polyamide resins and amine formaldehyde resins.

2. A fire-retardant paint comprising fire-resistant pigment components, volatile vehicle components and nonvolatile vehicle components consisting essentially'offrom about to about 60%raw isano oil. 2 a a 3. An intumescent film-forming vehicle for a fireretardant paint comprising volan'le vehicle components.

and non-volatile vehicle components consisting essentially of at least 10% raw isano oil and at least 5% of'a resinous compound selected from the polyamide resins and amine formaldehyde resins.

4. A vehicle for a fire-retardant paint comprising volatile vehicle components and non-volatile vehicle components consisting essentially of from about 10% to about 60% raw isano oil, from about 15% to about of a vegetable drying oil; and from about 5% .to about 25%. of a resinous compound selected from the class consisting of polyamide resins and amine formaldehyde resins.

5. An intumescent film-forming vehicle for a fire-retardant paint comprising volatile components and nonvolatile components consisting essentially of 10% to raw isano oil and 5% to 25% of a resinous compound selected from the class consisting of polyamide resins and amine formaldehyde resins.

6. A vehicle for a fire-retardant paint comprising volatile components and non volatile components consisting essentially of at least 10% raw isano oil, at least 15 of a vegetable drying oil and at least 10% chlorinated paraffin, and at least 5% ofa resinous compound selected from the class consisting of polyamide resins and amine formaldehyde resins.

7. A vehicle for a fire-retardant paint comprising volatile vehicle components and non-volatile vehicle components consisting essentially of from 10% to 60% raw isano oil and 5 to 25% polyamide resin.

8. A vehicle for a fire-retardant paint comprising volatile vehicle components and non-volatile vehicle compo-. nents consisting-essentially of 13 to 30% raw isano oil, 7 to 11% polyamide resin.

9. A vehicle for a fire-retardant paint'c'omprising vola-" tile vehicle components and non-volatile vehicle components consisting essentially of 27.2% raw isano oil and 10.2% polyamide resin.

10. A vehicle for a fire-retardant paint comprising volatile vehicle components and non-volatile vehicle compo: nents consisting essentially of from 10% to 60% raw isano oil and 5 to 25% melamine formaldehyde resin.

11. A vehicle for a fire-retardant paint comprising volatile vehicle components and non-volatile vehicle compo-. nents consisting essentially of from 10% to 60% raw isano oil and 5 to 25% urea formaldehyde resin. l2 Avehicle for-a fire-retard ant paint comprising volatile vehicle components and non-volatile vehicle components consisting essentially of from 10% to 60% raw isano oil and 5 to 25 triazine formaldehyde resin.

Refel encesCited in the fileof this patent UNITED STATES PATENTS OTHER REFERENCES Official Digest No. 347,7pp. 982 .996,'Dec. 1953..

class consisting of 

1. A FIRE-RETARDANT PAINT EFFECTIVE TO FORM A FILM HAVING INTUMESCENT PROPERTIES WHEN SUBJECTED TO HEAT, COMPRISING PIGMENT, VOLATILE VEHICLE COMPONENTS AND NONVOLATILE VEHICLE COMPONENTS CONSISTING ESSENTIALLY OF AT LEAST 10% RAW ISANO OIL AND AT LEAST 5% OF A RESINOUS COMPOUND SELECTED FROM THE CLASS CONSISTING OF POLYAMIDE RESINS AND AMINE FORMALDEHYDE RESINS. 